1. Field of the Invention
The present invention relates to a sampling and dispensing apparatus for automatically sampling and dispensing a blood specimen from a test tube for containing a blood specimen.
2. Description of the Related Art
In the case of carrying out a variety of blood inspections such as biochemical analysis, a test tube having a blood specimen contained therein is placed in a centrifugal separator, and a blood centrifugal separation process is carried out as preprocessing thereof. Next, sampling the blood serum contained in the test tube and dispensing the sampled blood specimen in a predetermined inspection container is carried out.
FIG. 5 is a view showing a general state of the blood specimen contained in the centrifugally separated test tube. Blood serum β and a blood clot γ are separated from each other inside a test tube 11. This separation is carried out by a separating agent δ such as silicon such that a boundary face between the blood serum β and the blood clot γ is clearly segmented. Namely, the centrifugally separated blood specimen is divided into three layers in order of the blood serum β, separating agent δ, and blood clot γ from the top part of the test tube 11.
Therefore, when the blood serum β is sampled in the test tube 11 supported with an opening being upwardly set, a hollow, conically shaped sampling and dispensing probe formed in sharpened distal end shape is inserted from above the test tube 11, and only the blood serum β is sampled by an air type suction mechanism (not shown). Next, the sampling and dispensing probe having the blood serum β sampled therein is moved to a predetermined position, and the blood serum β is dispensed relative to a predetermined inspection container.
However, the blood serum β contained in the test tube 11 is extremely small in amount, and the distance from the liquid level to a bottom face (the top face of the separating agent δ) is short. Moreover, irregularities may occur on the top face of the separating agent δ, and the separating agent δ may be inclined. Therefore, when vacuum suctioning is carried out by the sampling and dispensing probe, a distal end opening of the sampling and dispensing probe abuts against the separating agent δ, and the distal end opening is blocked. The blood serum cannot be sampled smoothly.
When the blood serum β is vacuum-suctioned by the sampling and dispensing probe, it is known that a sampling auxiliary member having a flattening member at a distal end part of a shaft is inserted into the test tube 11, and the separating agent δ is pushed by the flattening member, thereby allocating a space for vacuum-suctioning the blood serum β by the sampling and dispensing probe (for example, Jpn. Pat. Appln. KOKAI Publication No. 9-304398).
However, even if the separating agent δ contained in the test tube 11 is flattened by using the sampling auxiliary member as described above, the blood serum β contained in the test tube 11 is extremely small in amount, and the distance from the liquid level to the bottom face (the top face of the separating agent δ) is short. Therefore, there still persists a problem that, when vacuum-suctioning is carried out by the sampling and dispensing probe, the distal end opening of the sampling and dispensing probe abuts against the separating agent δ, and the distal end opening is blocked, disabling smooth sampling.